Various scientific and patent publications are referred to herein. Each is incorporated by reference in its entirety.
Recent advances in miniaturization have led to the development of systems capable of performing chemical and physical processes on a micro-scale. Such systems have application to analytical and medical instrumentation, industrial process control equipment, liquid and gas phase chromatography, and detection of chemical and biological agents. One type of microfluidic system is the “microfluidic chip,” which term generally refers to a device having channels, chambers, or other features on the micron or sub-micron scale, i.e., having at least one cross-sectional dimension in the range of from about 0.1 micrometer to about 500 micrometers.
In some cases, microfluidic chips may incorporate biochemistries or biological molecules present at one or more locations on or within the chips, such molecules being used to purify or detect analytes present in samples introduced to the chips. However, many biochemicals, e.g., nucleic acid probes, can tolerate only mild environmental conditions. As a result, certain manufacturing processes applied to microfluidic chips, such as thermal plastic melt welding, pose a challenge to incorporating biochemicals within microfluidic chips.
Forming features having characteristic dimensions in the range of micrometers or in the range of tens of micrometers, as is specified in certain microfluidic applications, poses further challenges. One method for forming features is injection molding, which entails injecting a liquid or molten plastic, metal, or other material at high pressure into a mold having the shape of the desired product. Such methods, however, face challenges in forming structures in the micrometer size range.
Given the described limitations in the current state of the art, there is a need for methods for efficiently producing devices having micrometer-scale features, such devices being fabricated in a way that does not adversely affect biomolecules or other functionalities present on or within the devices.